This is a multicenter trial (36 universities) testing the efficacy of CNTF ciliary neurotropic factor) in slowing the progress of ALS in human patients. It is double blind, placebo controlled with 1/3 of pts receiving 30 mgm/kg 3 x weekly, 1/3 15 mgm/kg 3 x weekly and 1/3 receiving placebo 3 x weekly.